The present invention relates to the field of construction and more particularly it relates to building roofing structures.
The present invention can be used to advantage in construction of various buildings, for example exhibition halls.
Selection of the roofing structure plays an important role in the construction of various buildings.
Arch coverings are often used as basic structures for covering large spans. For example, a hangar in Bristol-Filton airport has a roof wherein the basic load-bearing elements are arches with tie beams. The tie beams interconnect the ends of the arches and, in addition, are fastened to them by hangars along the span between the supports. Girders are placed on the arches to support the roofing made of steel profiled decking.
A disadvantage of this structure lies in that the material of the roofing, i.e. the profiled steel decking takes no part in the load-bearing function of the arch and serves for protective purposes only. Moreover, when the roofing is leveled with the arches, both the roofing surface and the internal spaces of the building are larger than they are in the case of a flat roof which results in higher expenditures for heating the building.
Also known in the previous art is the roofing structure of standard hangars that were contructed in Germany in 1938 - 1941 . This structure consisted of a three-dimensional arch of a triangular section whose side faces were formed by a number of trapezoidal steel elements which acted as protection and simultaneously took part in the load-bearing function of the arch.
A disadvantage of this structure lies in that the roofing is located level with the arch which, like in the preceding example, increases the expenses for maintenance of the building.
Still another known structure of a hangar built in 1939 in Milan comprises an arch as the basic load-bearing element of the roofing. The ends of the arch are interconnected by a tie in the form of a rigid truss. Furthermore, the tie and the arch are interconnected along the span by double hangars. For arranging the roofing in the plane of the ties, there are provided trusses set perpendicularly to the ties and functioning as secondary beams. On these trusses are laid girders which support a slate roofing.
The disadvantages of this structure reside in a heavy weight and considerable difficulties in its erection since the roofing consists of a great number of elements; moreover, the roofing serves for protection only, and takes no part in the load-bearing function of the ties.